Typically, in rotating coalescer filter assemblies, a filter element rotates within a housing to filter a fluid. In order to allow the filter element to rotate, a bearing may be positioned above the filter element to guide the movement and rotation of the filter element relative to the housing. However, the bearing may create problems within the filter assembly. For example, the bearing may not stay sufficiently lubricated, potentially resulting in a shorter life of the filter assembly. Additionally, while grease and/or a seal may be used in attempt to maintain the lubrication, such measures also increase the cost and the required materials for the filter assembly, while also increasing the level of the drag or friction within the filter assembly.
Additionally, the bearing above the filter element may create a potential by-pass route for the unfiltered fluid and/or the bearing lubricant between the clean and dirty sides of the filter element. This may result in a decrease in the efficiency of the filter assembly. In order to prevent such a by-pass from occurring, a seal may also be used within the filter assembly. Such a seal, however, may increase the cost, the required materials, and the drag within the filter assembly. Still further the bearing above the filter element may require a sliding adjustment (e.g., a fit with clearance, compared to a tight adjustment which is a fit without a clearance (e.g., a press-fit)) in order to authorize servicing. The sliding adjustment may create a rolling effect (e.g., when the inner ring of the bearing rotates in relation to the shaft), which may damage the axial shaft of the filter in operation.